01U07TAMLiang, Controlled Assembly of Metallic Clusters for High-Performance Optical Devices

到目前为止，光场仅被视为传播波。然而，原子尺度的物体也可以看到近场。因此，纳米金属簇的精确制造可以弥合近场和远场之间的差距，从而产生具有精确工程光学特性的全新一代光学材料和器件。为了实现这些目标，需要精确制造纳米金属结构，其特征尺寸在几纳米的尺度上。一种新型的金属纳米结构的可控组装工艺将联合收割机结合化学自组装和纳米光刻的优点，同时消除各自的缺点。这是通过使用扫描探针显微镜（SPM）通过组合电化学和机械刺激进行掺杂，然后进行受控的纳米金属生长和/或稳定化来完成的。这种受控组装技术能够实现纳米级定位精度，能够生产高晶体质量的金属，并且即使对于晶片集成制造所需的复杂金属结构也是可再现的。这项工作最初将集中在宽度为50 - 150 nm的光学纳米线上。 该研究团队由材料科学，非线性和量子光学方面的专家组成，并让学生从事多学科工作。 其影响可能是深远的。例如，高阶非线性光学和拉曼相互作用可以在毫瓦功率水平下产生。单分子发射体将看到如此大的真空拉比频率，以至于自发发射的阻尼效应将变得可以忽略不计。这些纳米光学器件将有广泛的国防部应用，从超灵敏的化学和生物传感器，高温红外探测器，到新型的多光谱焦平面阵列。

Until now, optical fields have been treated only as propagating waves. However, atomic-scale objects can also see the near-field. It follows that the precise fabrication of nano metallic clusters can bridge the gap between near-field and far-field, resulting in a whole new generation of optical materials and devices with precisely engineered optical properties. To achieve these goals, the precise fabrication of nano-metallic structures is required, with feature sizes on the scale of a few nanometers. A novel controlled assembly process for metallic nano-structures will combine the best features of chemical self-assembly and nano-lithography, while eliminating the disadvantages of each. This is done by doping through combined electrochemical and mechanical stimulation using a scanning probe microscope (SPM), followed by controlled nano-metal growth and/or stabilization. This controlled-assembly technique enables nanoscale positioning precision, is able to produce high-crystal-quality metal, and be reproducible, even for complex metallic structures as needed for wafer-integrated fabrication. The work will concentrate initially on optical nano-wires with widths on the order of 50 -150 nm. The research team is formed with experts in material science, and in non-linear and quantum optics and engages students in multi-disciplinary work. The impact of this could be far-reaching. For example, high order nonlinear optical and Raman interactions can be produced at milliwatt power levels. Single molecule emitters will see such large vacuum Rabi frequencies that the damping effects of spontaneous emission will become negligible. These nano-optic devices will have a wide range of DoD applications, ranging from ultra-sensitive chemical and biological sensors, to high temperature IR detectors, to novel multi-spectral focal plane arrays.